Freshman year I went through an unexplained fugue state and stopped going altogether for a while. Altogether I missed at least a couple of months' worth. The school's disciplinarian had no tolerance for me thanks to the trouble my elder sister inadvertently caused her, and so threatened me and otherwise made her vehemence clear. Everyone else in the school, recognizing that I was obviously going through something (as I'd never previously been in trouble, for anything), were supportive. We never worked out what was going on with me, and the disciplinarian hated me from that moment on.
Later, in either Junior or Senior year, my friend and I left the campus before school started (long story, but she needed comfort), were apparently spotted doing so, and both served in-school suspension, the current form of detention.
I wasn't a troublemaker or a "goodie two shoes." Aside from those incidents I tended to drift my way through causing virtually no disturbances in either regard.